In a wide range of medical treatment procedures, local therapeutic agent delivery through an open-ended delivery catheter, sheath or needle placed within a vein or artery of a body cavity is commonly used for systemic deliverable liquid and embolic agents. Hence, clinicians must pre-calculate the medication dose for its efficacy after dispersion following delivery within the body, as the medication quickly dilutes and diffuses to a significantly less concentration immediately after delivery with such open ended medical injectable devices placed within the body. Placement of one or more holes along the side wall of such delivery devices have been clinically shown to cause tissue damage under injection delivery pressures, creating a damaged area within the body. Such side wall hole delivery devices also do not provide for image viewable zones of delivery as they are indicated for systemic delivery of medication. Non-porous elastomeric and angioplasty balloon catheters have also been used to deliver therapeutic agents directly to treatment sites within a body cavity by creating systemic occlusion of the vessel or narrow lumen with the same undesirable clinical effects when the medication is uncontrollably delivered by syringe via jetting fluid out through the central lumen of such delivery device generally located on the distal end and side holes. Such devices provide no means to concentrate the medication without inducing either occlusion or trauma to the vessel, and without any image guidance means to determine where the concentration of medication is delivered. Therefore an atraumatic medication delivery device that provides a means to determine under image guidance the location of the highest concentration of medication delivered locally to a targeted treatment site, prior to systemic dilution and without vessel occlusion, may increase the efficacy and decrease the systemic loss of a prescribed medication bolus during injection, and reduce the need for larger volumes and concentrations of medication generally prescribed for systemic dilution during IV injection.
Micro porous balloon delivery devices have been demonstrated to enable a therapeutic agent to be delivered through small pores formed in the balloon portion itself creating a pressure limiting means by which to deliver a medication during inflation and vessel occlusion. A significant shortcoming common to such drug eluting porous conventional balloon catheters is that the multiple bonding zones required for attaching a porous delivery balloon to the catheter shaft, and its size, length and geometry of the balloon portion around the external shaft of the catheter limits the ability of the catheter to track around tortuous anatomy, significantly restricting access to various hard to reach and remote body cavity treatment sites for localized delivery of therapeutic agents. For example, both conventional porous and non-porous balloon catheters may encounter difficulty accessing smaller vessel treatment sites having narrow, or partially occluded or diseased lumens leading up to the treatment site. In addition, the sites at which conventional balloon catheters are able to be positioned for treatment are limited by the size and geometry of the folded balloon material and bonding sites on the outside of the catheter shaft. Further, in those situations in which a balloon catheter is able to access more difficult to reach sites, or smaller sites, the expansion of the medication delivery balloon itself to release the therapeutic agent may not be able to be positioned to maximize drug concentration at the treatment site without causing damage to the narrowed channel or vessel. In some instances, the damage may be caused by a jetting action of the fluid emitting from the balloon or delivery device and impacting the tissue. In these situations, conventional balloon catheters therefore may not be suitable for localized delivery of therapeutic agents to many narrow, partially occluded and remote treatment sites within the body.